The disclosed embodiments of the present invention relate to processing an image data, and more particularly, to an image data compression apparatus for referring to at least one characteristic value threshold to select a target compression result from candidate compression results of one block and related method thereof.
Data compression is commonly used to reduce the amount of data stored in a storage device. Regarding an overdrive technique applied to a liquid crystal display (LCD) panel for example, it artificially boosts the response time by increasing the driving voltage used to make a liquid crystal cell change its state. The overdrive voltage of one liquid crystal cell (i.e., one pixel) is determined by a pixel value in a current frame and a pixel value in a previous frame. Therefore, an image data of the previous frame has to be recorded into a frame buffer for later use. In general, the image data of the previous frame will be compressed before stored into the frame buffer. If a compression approach which provides a lower compression ratio is employed to compress the image data of the previous frame, the frame buffer is required to have a greater storage capacity; otherwise, the frame buffer cannot accommodate all of the compressed image data of the previous frame. However, if a higher compression ratio is employed, a difference between an original image data and a recovered image data derived from the compressed image data will become more significant, leading to degradation of the display quality.
In view of above, there is a need for an image data compression method and apparatus which can adopt an adequate compression approach to compress the image data of each frame.